Why Don't We Build Better Houses?

Did you know that the solar house was a popular concept in the 1940s, and that architects like Fred Keck, an American modernist architect based in Chicago, Illinois, could save their clients 30–40% on heating energy by using simple passive techniques? My book, The Solar House: Pioneering Sustainable Design, describes some of the early experimental houses that used active-solar heating systems. One question I do not address in the book, but that I am always asked when I give public talks, is why we aren’t building houses like that now. If simple passive measures were common and effective in the 1940s, why aren’t they used by architects and home builders today?